Bf-109: 7 degrees flaps for increased rate of climb?

[FTC_Mephisto]

Just reading Walter Schuck's autobiography* and came across an episode where the author is scrambled to chase a light-weighted reconnaissances Spitfire and needs to climb to catch a much faster plane in a dive (crude translation from German):

 

"Because Gyako [Walter Schuck's wingman] was slightly lagging I concluded that he was not aware of a trick to keep your flaps slightly extended in a climb. At 7 degrees of flaps one could achieve the optimal angle of climb with the Me 109 and could, even without risking a stall, really soar steeply."

 

Plane used was a Bf 109 G-6. At the end he successfully climbs to 9000m and is able to catch the Spitfire in a dive and shoot it down from dead 6 o'clock. Russian pilot exits with a parachute. Overall ammunition usage: 5 shells from MG 151/20 and 30 from MG 131. It is his victory number 125 and the 12th plane shoot down within a 24 hours period on 17/18 June 1944.

 

Would be interesting to test this trick in IL-2 if not already done. 

 

*Abschuss! Von der Me 109 zur Me 262 Erinnerungen an die Luftkämpfe beim Jagdgeschwader 5 und 7 [Victory! From the Me 109 to the Me 262 Memories of the Dogfights with Fighter Wing 5 and 7]

Edited June 15, 2020 by Mephisto

[Bremspropeller]

You'll never increase your RoC by adding drag.

 

I'm calling BS.

[JG27*PapaFly]

17 hours ago, Mephisto said:

Because Gyako [Walter Schuck's wingman] was slightly lagging I concluded that he was not aware of a trick to keep your flaps slightly extended in a climb. At 7 degrees of flaps one could achieve the optimal angle of climb with the Me 109 and could, even without risking a stall, really soar steeply."

Perhaps something got lost in translation here.

 

By deploying flaps you can climb at a steeper plane attitude / slower speed, whichever you need. Depending on the tactical situation, a pilot might actually choose to do so. One example would be when there's the danger of overshooting you opponent in a climb. Your lift-to drag ratio and climb rate will be worse, but you will be able to slow down and maintain a position on your opponent's low six.

I don't know whether the mentioned flap setting improves engine cooling, so that the climb can be performed at a higher power setting.

[=X51=VC_]

I was going to say, optimising climb angle and climb rate are different things. Climbing more steeply may be preferrable sometimes, but more drag should reduce total energy gain over time.

 

Unless there's a weird quirk of the 109 aerodynamics. For example, if the extra speed and/or AoA you'd need to maintain climb attitude with no flaps cause more induced drag than getting the same lift at lower AoA and IAS with 7 degrees of flaps. Combined with higher excess thrust at lower speed and a steeper climb angle it might net you greater vertical velocity component?

 

The other thing that doesn't make sense is trying to optimise climb angle against an enemy diving away from you. You're not at risk of overshooting, I maybe getting higher first to maximise your level TAS then diving to catch up is better overall than trying to intercept a diving enemy with a shallow climb?

Edited June 16, 2020 by =X51=VC_

[69th_Panp]

11 hours ago, JG27_PapaFly said:

Perhaps something got lost in translation here.

 

By deploying flaps you can climb at a steeper plane attitude / slower speed, whichever you need. Depending on the tactical situation, a pilot might actually choose to do so. One example would be when there's the danger of overshooting you opponent in a climb. Your lift-to drag ratio and climb rate will be worse, but you will be able to slow down and maintain a position on your opponent's low six.

I don't know whether the mentioned flap setting improves engine cooling, so that the climb can be performed at a higher power setting.

Nothing lost in translation here.

I have his book in English and it is what it is.

He used this technic in quite a few of his fights with Russian planes to climb at a faster rate that his opponents and would then turn back onto them and shoot them down.

He truly was a master of the 109

 

You really need to read the entire story of the encounter with the reconnaissance's Spitfire to understand what and how it happened.

 

Walter Schuck's autobiography is a great read on the eastern front battles, well worth the time and money!

Edited June 16, 2020 by 69th_Panp

[ITAF_Rani]

On 6/15/2020 at 7:21 PM, Mephisto said:

Just reading Walter Schuck's autobiography* and came across an episode where the author is scrambled to chase a light-weighted reconnaissances Spitfire and needs to climb to catch a much faster plane in a dive (crude translation from German):

 

"Because Gyako [Walter Schuck's wingman] was slightly lagging I concluded that he was not aware of a trick to keep your flaps slightly extended in a climb. At 7 degrees of flaps one could achieve the optimal angle of climb with the Me 109 and could, even without risking a stall, really soar steeply."

 

Plane used was a Bf 109 G-6. At the end he successfully climbs to 9000m and is able to catch the Spitfire in a dive and shoot it down from dead 6 o'clock. Russian pilot exits with a parachute. Overall ammunition usage: 5 shells from MG 151/20 and 30 from MG 131. It is his victory number 125 and the 12th plane shoot down within a 24 hours period on 17/18 June 1944.

 

Would be interesting to test this trick in IL-2 if not already done. 

 

*Abschuss! Von der Me 109 zur Me 262 Erinnerungen an die Luftkämpfe beim Jagdgeschwader 5 und 7 [Victory! From the Me 109 to the Me 262 Memories of the Dogfights with Fighter Wing 5 and 7]

Thanks to have underlined  the attention on this pilot...just ordered the book!!

Edited June 16, 2020 by ITAF_Rani

[69th_Panp]

It will give you a better understanding of the eastern front and what tactics both sides used.

Like I said it is  great read from a great pilot

[Gustav_Hagel]

On 6/15/2020 at 2:32 PM, Bremspropeller said:

You'll never increase your RoC by adding drag.

 

I'm calling BS.

7 degree flaps are more benefit for lift than drag, maybe you should educate yourself a little bit more of simple aerodynamics before saying things are BS?

In case you are in doubt, look at any book of Performance and Stability, also here explains in simpler words: https://www.boldmethod.com/learn-to-fly/aircraft-systems/how-flaps-work/

[Bremspropeller]

2 minutes ago, SCG_Gustav_Hagel said:

7 degree flaps are more benefit for lift than drag, maybe you should educate yourself a little bit more of simple aerodynamics before saying things are BS?

 

The L/D decreases nonetheless. if it didn't, two things would happen:

 

1) Messerschmitt would write a note into the pilot's operating handbook, that max RoC is achieved with 7° of flaps.

2) Messerschmitt would change the wing to benefit from the added L/D at that flap-setting.

 

I already have a Master's Degree in Aerospace Engineering - I don't need Boldmethod or any other quack website to tell me about aerodynamics.

 

[Gustav_Hagel]

29 minutes ago, Bremspropeller said:

 

The L/D decreases nonetheless. if it didn't, two things would happen:

 

1) Messerschmitt would write a note into the pilot's operating handbook, that max RoC is achieved with 7° of flaps.

2) Messerschmitt would change the wing to benefit from the added L/D at that flap-setting.

 

I already have a Master's Degree in Aerospace Engineering - I don't need Boldmethod or any other quack website to tell me about aerodynamics.

 

Nope, L/D doesn't always decrease. Again, educate yourself. Handbooks state ~15º for take off iirc (because it does increase LIFT!). Flaps reduce the max AoA though and that's why it's not widely used in every situation.

https://www.researchgate.net/figure/Illustration-of-the-effect-of-flaps-on-the-lift-curve-The-numbers-shown-are-typical-of_fig1_273923634

https://www.quora.com/At-what-point-do-flaps-provide-more-drag-than-lift

Read the introduction on page 4 of the paper (or page 5 of the pdf) http://naca.central.cranfield.ac.uk/reports/arc/rm/2622.pdf

Here there's an AMAZING graph on Appendix A https://www.mdpi.com/2073-8994/12/5/828/htm
Note: "As explained in the introduction, the TEF concept is based on lift increase, when the flap is deployed on the pressure side (negative β angles), and lift decrease when the flap is deployed on the suction side (positive β angles) of the airfoil."
The graph: 

Again, read first, educate yourself and then comment something useful.

Edit: Just saw you said you had a degree, maybe it's time to throw it away? Or time to educate yourself and read some more papers.

Edited June 18, 2020 by SCG_Gustav_Hagel

[Aap]

Man, you don't need aerospace education to see your approach is flawed here. If wing's lift-capability was the only factor in affecting the rate of climb, why settle to 7 degree flaps and not full flaps? Rhetorical question.

 

Classical high school level physics gets you far enough here. If plane is affected by the following forces: thrust, drag, lift and gravity, what is the sum vector of these? Flaps add lift and drag, what is the result vector now? I am pretty sure that over 99% of aircraft wings have been designed to get better rate of climb with higher speed, which also increases lift (now we come to this aerospace education part) rather than increasing drag (lowering speed). 

 

The purpose of flaps is to get more lift, so you can stay in the air, when your airspeed is low. Sure, if your intention is to climb at 170 km/h, then it is better to use flaps, otherwise you would fall out of sky, but if you intend to put your engine power to good use and climb at 300 km/h, then it does not make sense to increase drag.

[Bremspropeller]

3 hours ago, SCG_Gustav_Hagel said:

Nope, L/D doesn't always decrease. Again, educate yourself. Handbooks state ~15º for take off iirc (because it does increase LIFT!). Flaps reduce the max AoA though and that's why it's not widely used in every situation.

https://www.researchgate.net/figure/Illustration-of-the-effect-of-flaps-on-the-lift-curve-The-numbers-shown-are-typical-of_fig1_273923634

https://www.quora.com/At-what-point-do-flaps-provide-more-drag-than-lift

Read the introduction on page 4 of the paper (or page 5 of the pdf) http://naca.central.cranfield.ac.uk/reports/arc/rm/2622.pdf

Here there's an AMAZING graph on Appendix A https://www.mdpi.com/2073-8994/12/5/828/htm
Note: "As explained in the introduction, the TEF concept is based on lift increase, when the flap is deployed on the pressure side (negative β angles), and lift decrease when the flap is deployed on the suction side (positive β angles) of the airfoil."
The graph: 

Again, read first, educate yourself and then comment something useful.

Edit: Just saw you said you had a degree, maybe it's time to throw it away? Or time to educate yourself and read some more papers.

 

Now, do handbooks also state that 7° of flaps increase RoC?

 

 

The paper you quote is a 2D analysis of a low-chord un-gapped idealized flap using piezoacuators. It doesn't account for 3D-flow in general, gap-drag, iduced drag at the gates and trim-drag. Real airplanes are a bit more complex than just thrashing an idealized airfoil through a nummerical solver and plotting 2D Cl over Cd.

 

Racing-gliders achieve L/Dmax at neutral flap-positions. They already have a trailing-edge reflex of 5'ish degrees as part of their normal wing-optimization, which is similar to what any airplane undergoes during design and flight-testing. You can be sure that Messerschmitt has spent several hundred (if not thousand) hours, optimizing the aircraft's performance.

Had there been any funny tricks - you'd read about it in the manual or on a technical change.

 

Nice try, though...

 

 

 

 

[Gustav_Hagel]

5 hours ago, Bremspropeller said:

 

Now, do handbooks also state that 7° of flaps increase RoC?

 

 

The paper you quote is a 2D analysis of a low-chord un-gapped idealized flap using piezoacuators. It doesn't account for 3D-flow in general, gap-drag, iduced drag at the gates and trim-drag. Real airplanes are a bit more complex than just thrashing an idealized airfoil through a nummerical solver and plotting 2D Cl over Cd.

 

Racing-gliders achieve L/Dmax at neutral flap-positions. They already have a trailing-edge reflex of 5'ish degrees as part of their normal wing-optimization, which is similar to what any airplane undergoes during design and flight-testing. You can be sure that Messerschmitt has spent several hundred (if not thousand) hours, optimizing the aircraft's performance.

Had there been any funny tricks - you'd read about it in the manual or on a technical change.

 

Nice try, though...

 

 

 

 

You can keep talking, your lack of proof and just plain arguments show how bad you are at your analysis and engineering. Keep thinking you are right and every book and other source is wrong, you will go far this way?

You should know by the way there's a slight difference from engineering back then and now, that we have CFD.

Found this paper, what will be your excuse now? Maybe it's wrong and you should tell to all those scientists and engineers, maybe tell NASA this paper is wrong too: https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20150006019.pdf

I don't brag about my education, I'm currently doing my Bachelors work in Physics and at the same time doing Aerospace Engineering in one of the best universities in my country, which is actually one from the Federal government. My Engineering Bachelors are the same level as your Bachelor+Master in Europe, since Engineering is 5 years rather than 3 as in most Engineerings from Germany, while Physics 4. So before you start bragging and coming here with ad hominem arguments, present us some information proof based rather than unfounded plain words.

Now back to OP statement from the book. It was never mentioned RoC, but rather angle of climb. This is well known since flaps increase lift (until a certain degree) and reduces the minimum stall speed. What OP might be referring is rather than RoC but Climb Gradient, which, in this case could make sense, as flaps increase the lift for certain climb angle. The limitations are obvious as the max AoA is reduced and thus wouldn't be efficient compared to the case for 0º flap deflection, but as the statement shows it's mininum climb speed (close to stall) related we can pretty much deduce Walter Schuck is talking about the Gradient itself. Would be interesting to see if nothing was also lost in translation as we can't say anything with total certainty since we don't have any 3D model to analyze it that right now.

Edited June 19, 2020 by SCG_Gustav_Hagel

[Bremspropeller]

7 hours ago, SCG_Gustav_Hagel said:

You can keep talking, your lack of proof and just plain arguments show how bad you are at your analysis and engineering. Keep thinking you are right and every book and other source is wrong, you will go far this way?

 

You're the dude quoting the 109 climbs better at 7° flaps, which is against common wisdom, so the burden of proof is on you. Sorry, pal!

So far, you have managed to quote some papers that prove exactly zero about increasing RoC by using flaps.

 

Quoted a paper on wind-turbine profile optimization, which stated that introducing a trailing-edge reflex increases L/D of the wing. The airfoils used for research were all fairly symmetrical, so adding a little downwash does help them. That's pretty much known since the earlies days of laminar profile design in the 1940s. Nothing new, and especially nothing ON TOPIC, since that reflex is already part of the wing-optimization and has nothing to do with actual trailing edge flaps BEYOND that reflex on an airplane.

 

 

 

All the other sources you brought up say exactly zero about the problem at hand. The only interesting thing about the RAE-report was the confirmation that dive recovery flaps are working by introducing a pitch-up moment, rather than "increasing lift".

 

8 hours ago, SCG_Gustav_Hagel said:

Found this paper, what will be your excuse now? Maybe it's wrong and you should tell to all those scientists and engineers, maybe tell NASA this paper is wrong too: https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20150006019.pdf

 

So, help a troubled man:

Where does it state that RoC increases with flaps out?

 

8 hours ago, SCG_Gustav_Hagel said:

I don't brag about my education, I'm currently doing my Bachelors work in Physics and at the same time doing Aerospace Engineering in one of the best universities in my country, which is actually one from the Federal government. My Engineering Bachelors are the same level as your Bachelor+Master in Europe, since Engineering is 5 years rather than 3 as in most Engineerings from Germany, while Physics 4. So before you start bragging and coming here with ad hominem arguments, present us some information proof based rather than unfounded plain words.

 

So far, your claim isn't backed by any evidence.

 

8 hours ago, SCG_Gustav_Hagel said:

You should know by the way there's a slight difference from engineering back then and now, that we have CFD.

 

I do. That's why I'm wondering where you're hiding all that flight-test-evidence of the 109 climbing better at 7° flaps out.

 

8 hours ago, SCG_Gustav_Hagel said:

Now back to OP statement from the book. It was never mentioned RoC, but rather angle of climb. This is well known since flaps increase lift (until a certain degree) and reduces the minimum stall speed. What OP might be referring is rather than RoC but Climb Gradient, which, in this case could make sense, as flaps increase the lift for certain climb angle. The limitations are obvious as the max AoA is reduced and thus wouldn't be efficient compared to the case for 0º flap deflection, but as the statement shows it's mininum climb speed (close to stall) related we can pretty much deduce Walter Schuck is talking about the Gradient itself. Would be interesting to see if nothing was also lost in translation as we can't say anything with total certainty since we don't have any 3D model to analyze it that right now.

 

1) The thread is about increasing RoC.

2) Climb Gradient is not about AoA, it's about maximum lift. If that can be achieved at a lower AoA, it's fine. Problem is: There's too much drag to facilitate any benefit, when dopping flaps. That's why climb-gradient limited conditions require lower initial flap-settings on take-off.

3) Vx isn't all THAT close to stall.

4) No way! Schuck might be wrong after all?

 

[firdimigdi]

Maybe it was something specific to the profile of the 109's wing or even it's general aerodynamics. Some design flaw that when climbing at a certain angle and speed with 7 degrees of flaps was mitigated. A pilot with a keen ear might've of heard turbulent air and noticed that with a wee bit of flap the noise goes away and there you go no turbulence, less drag... It's all speculation unless we could put a G6 in a wind tunnel and find out...

Edited June 19, 2020 by Firdimigdi

[Aurora_Stealth]

Yeah think we've got to be a little careful here misreading what Shuck is doing. I'm reading Pierre Clostermann's book 'The Big Show' at the moment (another must read), when a similar situation occurs. Clostermann in his Spitfire Mk IX is on radar calibration exercise over Beauvais when he is intercepted by a "probably new variant Messerchmitt Bf 109 G" which is initially called out from the R/T operator.. the aircraft is shadowing him around 30,000 feet (9,000m). He waits to the last minute to break, and performs a steep climbing turn briefly and then flattens the turn which surprises the Luftwaffe pilot who overshoots and attempts in vain to cut the corner on him. The Bf 109 enters a stall and spin following the overshoot but recovers - however this is a fatal mistake at this point and the Bf 109 is eventually shot down in the dive. This in Sept 1943 so possibly a G-5 high altitude variant.

 

At these extreme altitudes (much above rated 7 - 8km altitude), the Bf 109 is going to struggle to produce as much lift (smaller wings) depending on the model and the second stage of the Merlin's supercharger seems to help in the thinner air up there. It makes sense in a tactical ploy however to increase that wing area slightly by opening up a little flap, and so adding just enough lift (at the cost of some L/D ratio) to temporarily keep the Bf 109 in the maneuver for a little longer and also to avoid the stall onset.. but lets be honest that energy will be draining away then at a slightly quicker rate due to the increased drag as well.

 

In other words its a quick fix to stay competitive in the fight but it won't last for too long. A Bf 109 will be more prone in general to stalling up there, because of the aforementioned factors at being at extreme altitude, hence why using a little flaps is a way of holding this off.

 

I also imagine, because the radiator is integrated into the flaps on the Bf 109 that 7 degrees flap is not causing as much excess drag compared to other fighter types with conventional flap setups i.e. just takeoff or landing flap positions.

 

One last thing - which astounded me when I read the title of this thread - and I promise here this is not me being revisionist... 7 degrees is the magic number for flaps I have been using in IL-2 over recent months with the Bf 109 G-14 and K-4 to tighten the turn against other similar turning fighters. I know it works through a process of elimination, as I tried 5 degrees and this was insufficient then pushed to 10 degrees which slowed me down too much and I lost ground in the turn..  seven was the sweet spot against the P-51. I managed to last 3 - 4 minutes in a furious turning contest with no fewer than six aircraft taking pot shots at me on Combat Box although this was a while ago as I'm flying other aircraft atm. I can confirm resolutely there is something of a sweet spot in this number.

Edited June 19, 2020 by Aurora_Stealth

[Bremspropeller]

12 minutes ago, Firdimigdi said:

Maybe it was something specific to the profile of the 109's wing or even it's general aerodynamics. Some design flaw that when climbing at a certain angle and speed with 7 degrees of flaps was mitigated. A pilot with a keen ear might've of heard turbulent air and noticed that with a wee bit of flap the noise goes away and there you go no turbulence, less drag... It's all speculation unless we could put a G6 in a wind tunnel and find out...

 

I don't think so. I'd say it's approaching certainty that had either Rechlin or any squadron figured out how to increase the (already very sparkling) RoC of the 109, one would have put that into the Bedienvorschrift. So far, we don't have any evidence this happened.

There could be a million reasons why Schuck thought the additional flaps helped (in doing whatever) - and it's probably lost in translation or it's lost by him remembering inaccurately, or by him just using an improper or unprecise term.

 

One thing it might have helped with is increasing the airflow through the radiator (lower deck-angle) and thus optimizing the outflow-flap setting.

But that's just a wild-ass-guess on my side, trying to find benefit in his statements.

 

From my experience in riding the backseat of a P-51 (and I guess @ZachariasX might vouch in on his experience in a Spit) I can assure you, there is absolutely no aerodynamic noise you can hear over the engine at normal climb-speeds. The engine absolutely drowns anything.

 

 

[firdimigdi]

15 minutes ago, Bremspropeller said:

I can assure you, there is absolutely no aerodynamic noise you can hear over the engine at normal climb-speeds. The engine absolutely drowns anything.

Yeah, I hear you (no pun intended).That was my experience the first time I sat in a race car. All I could hear was a roar and my excited brain deleted everything else. Subsequent times tho I started noticing more and more details. Same applied to the first time I fired a high calibre gun, all I heard was bang and missed out on a bunch of other cues that several thousand rounds later I can pick up on.

 

All I am saying is I don't know what a highly experienced pilot of a specific plane model could figure out that I can't in a single joyride - I'm rather inclined to believe "quite a lot". But yes I do agree that there is always the potential for things to have been lost either in translation, transcription or in memory.

Edited June 19, 2020 by Firdimigdi

[Canvas25]

On 6/16/2020 at 5:40 PM, 69th_Panp said:

You really need to read the entire story of the encounter with the reconnaissance's Spitfire to understand what and how it happened.

 

Would it be possible for someone who has this book to post this whole section? I think understanding what he was actually trying to do would be very helpful here.

[Gustav_Hagel]

5 hours ago, Bremspropeller said:

BLA BLA BLA know nothing, full of sophistry
 

Still looking where I stated RoC increased while deploying flaps, maybe it's possible as we know 7 degrees isn't a great deflection and you stated wrongly that L/D decreases no matter the flap deflection which is PLAIN wrong. Show me your papers and evidences, I'm still here waiting after a day.

I said it could be Gradient, since RoC wouldn't greatly benefit from that, and for the translation it is what mostly makes sense, I said after all it COULD be, it's an hypotesis and as someone who has a masters, you should well know the scientific method.

 

1) Not necessarily, if someone is trying to climb trying to achieve max gradient without flaps, might lag behind of someone who is using, check again the graph of AoA, flaps degree and Lift curve.
2) LIFT is increased to a certain point with flaps, check the papers. Seems like you have quite a problem to read and interpret.
3) maximum climb gradient IS close to stall (1.2 times, while optimal climb speed for 109 is around 230-250km/h, far from 160-180km/h), again, you are wrong about simple aerodynamics.https://encyclopedia2.thefreedictionary.com/maximum+gradient+speed#:~:text=The air speed at which,times the basic stalling speed.
4) Never said he was right, this is why we are discussing since  anecdotes are just anecdotes.
 

5 hours ago, Aurora_Stealth said:

 It makes sense in a tactical ploy however to increase that wing area slightly by opening up a little flap, and so adding just enough lift (at the cost of some L/D ratio) to temporarily keep the Bf 109 in the maneuver for a little longer and also to avoid the stall onset.. but lets be honest that energy will be draining away then at a slightly quicker rate due to the increased drag as well.

As I presented in many papers, L/D ratio doesn't decrease with flaps deployment, check graphs and papers. Despite that little mistake your thought could be right.

Edited June 19, 2020 by SCG_Gustav_Hagel

[ZachariasX]

5 hours ago, Bremspropeller said:

The engine absolutely drowns anything.

It absolutely does. It almost drowns out what you can hear in your headset. You fly these planes for hundreds of hours, you'll be hard of hearing. If I ever operated such an aircraft, I'd go with the latest noise canceling headsets available. It is alomost as bad as open cockpit.

 

5 hours ago, Firdimigdi said:

Maybe it was something specific to the profile of the 109's wing or even it's general aerodynamics. Some design flaw that when climbing at a certain angle and speed with 7 degrees of flaps was mitigated.

For me, the anecdote is plausible inasmuch as I tend to believe the pilot/author assuming that a tad of flaps helped him. By sheer aerodynamics it is not plausible. Aside from Brems' details, flaps do shorten take off run. They can give you the idea of better climb. But when you meter your performance, you will find out that the shorter takeoff run has nothing to do with better sustained climb.

 

The problem here is not so much the drag of the flaps, as flaps add relatively little drag. They are poor brakes. The problem is that you are flying too slow when flying at a speed where the wing profile with flaps set is efficient.

 

Think of a 109 as a racing aircraft. Same as a Spitfire. These aircraft are meant to go fast. Everything about them works best when going fast. Cooling especially! A 109 requires you to cool away an equivalent of 2000 hp. The faster you go, the easier that is. You can open the radiator, but THIS will create drag, far, far more than setting the flaps a notch.

 

If you climb a baby Spit (Mk.I - V), you should to climb with at least 160 mph or so, else your engine will cook off. As soon as you open your rad all the way, this is like pulling the hand brake, especially in climb. It is so bad that it can almost offset the added cooling by slowing the plane enough that the added cooling just compensates for the loss in speed. This commands you to go fast and shallow in climbs, making it possible that you can even have the rad set in the second notch ("40%" open) while climbing. In shot, you always want to go fast enough for keeping the rads in optimal flush (not closed!) setting.

 

In the B-26 Marauder, you have best climb at rated power with 15° cowl flaps. Setting them to 30° will result in 10% loss in climb. It is therefore imperative that you keep both oil and water/air coolers almost shut or in a flush position for a climb. At rated power, you require considerable airspeed for your coolers to deal with that heat. In level flight, go fast enough to fly with rads shut flush.

 

Now life can be cruel to you, as to the author of the anecdote and you really feel like going up as fast as possible and you just open up and try whatever you can. Life might even be good to you and you don't need to climb like mad. Then you can have (especially if you start with good flight speed) the situation, where you just open your rad and climb well below of what you could, but you keep your engine cool as you might need everything you have later on and not start out with an exhausted engine.

 

But whatever might be ideal, the choice is with the pilot. Thus:

On 6/16/2020 at 12:40 PM, JG27_PapaFly said:

Depending on the tactical situation, a pilot might actually choose to do so.

 

 

 

On 6/15/2020 at 7:21 PM, Mephisto said:

Would be interesting to test this trick in IL-2 if not already done. 

It's easy to do and if you were to try that, you just cook your engine. In game and in life. Theoretical best climb is a fixed % over stall speed. Reducing stall speed by setting flaps would mandate you to fly even slower and that will probably cook your engine. (Unless it's winter or you're lucky or whatever.) Just never climb slow and steep with these aircraft if you want to keep it.

 

 

When Willy says go fast, you go fast.

[Bremspropeller]

1 hour ago, SCG_Gustav_Hagel said:

...trololololo...

 

Congrats, you just upgraded onto my ignore list.

 

 

[Gustav_Hagel]

 

57 minutes ago, Bremspropeller said:

 

Congrats, you just upgraded onto my ignore list.

 

 

There we have a weak person with no proof based arguments. It's easy to ignore than to admit one is wrong, couldn't expect anything less from a sophist.?